By having a complete lack of insecurity and radiating a 'strong but warm' vibe. In this instance, the guy looks directly at the woman and smiles while others are saying stuff in the room. The attention creates a tension that isn't easily resolved by distraction through conversation. She becomes self conscious and 'folds' first, with her nerves getting the better of her after realising she was a lot more nervous than he was. Then, crucially, he looks away after 'winning' and doesn't look back, so when she checks again to see if he's still staring, he seems distant and non-needy, or at least less needy than her.
It communicates all the subtle non-verbal cues women use to gauge how high status you are. The pull-push with attention keeps it unpredictable and impactful, the ambiguity maximises curiosity, and curiosity=attraction, and it also makes her aware of how good the attention feels during the times its taken away,
Being huge and good looking helps of course, but even the best looking ripped guy can put women off by showing insecurity and anything that marks them as pathetic. Chad is just a fearless state of mind.
